exercise phys exam 2 Flashcards
PCr (phosphocreatine) is a buffer for ______
ATP
how long does it take to replenish PCr stores?
6 min
creatine loading:
20-25g/day for 5-7 days
what does creatine loading do?
helps increase performance for HIGH INTENSITY exercise
net ATP from glycolysis
2
what is the rate-limiting enzyme of glycolysis
phosphofructokinase
exercise stimulates GLUT4 transporter to:
transform into sarcolemma and let glucose in
insulin does what?
increases glucose in the cell. independent from exercise
blood glucose does what after 1 hr exercise
decreases
what helps prevent decrease of blood glucose during exercise?
ingestion of carbs
how much should you drink every 15-20 min. during exercise to maintain blood glucose?
8-12 oz of a 6% CHO drink
what are the two main pathways in skeletal muscle that increase glycogenolysis?
ephinephrine and Ca++ calmodulin
high intensity, short exercise utilizes what as fuel?
carbs
low intensity, long exercise utilizes what as fuel?
fats
moves lactate into mitochondria for oxidation via MCT (monocarboxylate transporter)
intracellular lactate shuttle
moves lactate to utilizing tissue (heart or slow twitch muscle)
extracellular lactate shuttle
energy in fat
9kcal/g
energy in carbs
4kcal/g
an increase in cyclic AMP causes:
increase PKA which activates hormone sensitive lipase
fatty acids are moved into mitochondrial matrix for beta oxidation by what enzyme?
carnitine transferase
what has to be present to use fat as energy?
carbs
In the Krebs cycle, what are the intermediates for beta oxidation of fats?
carbs
Highly trained individuals utilize ____ as fuel source more than others.
fat
crossover point:
when you start utilizing fats over carbs
rise of epinephrine in blood causes what?
utilize more fats
epinephrine increases with
duration and intensity of exercise
RQ=1
glucose
RQ=0.7
fats
RER:
respiratory exchange ratio, events at the lung, VCO2/CO2
In a trained individual, the time to reach steady state is ____
shorter
Rapid Repayment of oxygen debt
resynthesis of PC in muscles
restoration of muscle and blood O2 stores
slow repayment of oxygen debt
elevated hormones
elevated body temp
lactate removal
post-exercise elevation of HR and breathing
the graph for max rate of O2 consumption looks like:
linear increase then plateau
to remove lactate faster, ____
move threshold to the right during endurance training
lactate threshold:
good estimate of race pace during endurance exercise
to reduce rate of lactate removal, ____
decrease lactate threshold
How do you make the lactate removal much higher?
cool down or light exercise after workout to decrease build up of lactic acid
what environment won’t reach a steady state because there is a constant increase in O2 uptake?
hot and humid
what happens when you exercise for >10 min.?
ATP production is primarily from aerobic metabolism
Sprinting uses _____
PCr and anaerobic metabolism
mechanism of action for steroid hormones:
carrier protein in blood goes into cytoplasm
Growth Hormone helps maintain plasma glucose by 3 ways:
increases gluconeogenesis in liver
mobilizes FFA
decreases glucose uptake
Catecholamines do what to plasma glucose?
increase plasma glucose
pathway of cortisol secretion:
hypothalamus, CRH
anterior pituitary gland, ACTH
adrenal cortex
cortisol:stimulates gluconeogenesis
during exercise, glucagon____
increases plasma glucose
Insulin:
decreases plasma glucose, uptake of glucose into cells
lactic acid blocks mobilization of
FFA, lactic acid inhibits glycolysis by off setting catecholamines
Angiotensinogen was made in what organ?
the liver
angiotensinogen converts to what, by what enzyme?
converts to Angiotensin I by renin from kidney
Angiotensin I converts to what, by what enzyme?
converts to Angiotensin II by converting enzyme
Angiotensin II causes what
constriction of vascular smooth muscle
Angiotensin II then causes
aldosterone to be released, causing increased water and sodium retention
ADH
anti-diuretic hormone, water retention
when dehydrated, there is an increase in plasma osmolality. How does ADH respond?
ADH increases
hypovolemia
loss of body water due to increase of plasma osmolality
sweating decreases
hypoglycemic
low blood glucose, below 70 mg/dL
running economy
energy expenditure at a given running speed
5kcal =
1L o2 consumed
I met =
3.5 ml/kg/min
1 watt =
6.12 kpm/min
1kpm=
1 kgm
1 rev=
6m